Flexible foil-like webs and method of making the same



Oct. 26, 1965 J. LEFEBVRE 3,214,289

FLEXIBLE FOIL-LIKE WEBS AND METHOD OF MAKING THE SAME Filed Nov. 28.1961 Inventor 7:04 (I! [in I In:

Attorney United States Patent 1 Claim. 61. 117-422 This inventionrelates to new flexible foil-like webs and to methods of making thesame.

Sheets and tapes consisting of synthetic material are known which arereinforced with longitudinally extending filaments or threads.Suchsheets or tapes are intended for packing and binding purposes. Thesheets and tapes can in certain cases be provided on one side with anadhesive composition.

This invention relates to a flexible foil-like web which is reinforcedwith filaments or threads and which is especially suitable for packingpurposes, and to the production of tapes for binding purposes or themanufacture of adhesive tapes, especially self-adhesive tapes, the saidwebs or tapes being characterized by high strength values, for examplewith respect to tensile forces, bending, impact and the like and asregards cheapness.

The flexible foil-like web reinforced with filaments in accordance withthe invention comprises a large-mesh lattice material consisting ofvegetable, animal, mineral, artificial or synthetic filaments, in whichthe openings in the lattice are each closed by a thin skin of anelastomeric substance.

The lattice material can for example consist of an openweave fabric orof a material consisting of superimposed, unwoven warp and weft threadsor filaments. The spacing between the filaments (weft and warp) in thelattice material is preferably at least 1 mm. and is advantageously 2-4mm.; however, for special purposes, the filament spacings can besubstantially larger, for example 9 mm. or more.

The elastomeric material can consist of natural rubber or artificialrubber or another elastomeric synthetic material or mixtures thereof.According to one preferred embodiment, the elastomeric material isapplied from a latex or dispersion on to the lattice material.

The warp threads, consisting of vegetable, animal, mineral, artificialor synthetic filaments, may be arranged at a regular spacing from oneanother and united by weft filaments consisting of any suitable textilethreads, arranged at such a spacing from one another than an openarrangement or structure is obtained. Such a lattice material may beimpregnated with a bath containing dispersions consisting for example ofnatural rubber latex or a latex of an artificial rubber, the latex, ifdesired, being modified with thermosetting resins. Thermoplasticmaterials may likewise be used, preferably together with plasticisersand in paste or dispersed form (plastisols or organosols). Fibers inflake or powder form may also be added to any of these types ofimpregnants. The impregnation is carried out so that after drying andpolymerisation, a web is obtained in which the pores or interstices ofthe lattice material are closed by a thin film.

In a Web according to the invention, the weft filaments serve tomaintain the spacing of the warp filaments, and should have a tensilestrength suitable for the intended purpose, for example for packingpurposes, as adhesive tapes or adhesive sheets.

The webs can be subjected to treatments to make them water-proof,flame-proof, rot-proof or the like and may if desired be colored. Theproducts can also be used for the manufacture of garments and protectivecovers.

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The Webs are especially suitable for applying on one side an adhesive inorder to make adhesive tapes which have a strong and uniformlongitudinal strength.

The web is preferably manufactured by drawing the lattice material,immediately after having been manufactured (for example by weaving orsuperimposition of warp and weft threads), through a bath containing adispersion consisting of a natural latex or artificial rubber latex, orcontaining a plastisol, i.e. a dispersion of a plastic in a plasticiser.The bath may if required contain age resistors, modifying agents, forexample thermosetting resins, as well as vulcanising or curing agents oraccelerators. The bath may in addition contain pigments and/ ordyestuffs, as well as agents for flame-proofing purposes and/ or forpreservative purposes and for protection against micro-organisms, and/or for water-proofing purposes. If desired, fibers in the form of fiberdust or fiber flakes can also be present in the impregnation bath.

The underside of the flexible foil-like reinforced with filaments orthreads may be provided with an adhesive, more especially apressure-sensitive adhesive composition or a self-adhesive composition.If required, the top side of the web may carry an adhesive-repellinglayer.

The invention is illustrated in the accompanying drawings, in which:

FIG. 1 shows diagrammatically a large-mesh woven fabric, in which theopenings in the fabric are each closed by a thin film of an elastomericmaterial;

FIG. 2 is a diagrammatic view of an open lattice material, which ismanufactured from superimposed warp and weft threads and in which theopenings in the lattice are each closed by a thin film of an elastomericmaterial;

FIG. 3 shows a lattice material as a cross-section taken on the lineIll-HI of FIG. 2, in which the openings in the lattice are each closedby a thin film of an elastomeric material and which carries on itsunderside a self-adhesive composition and on its upper side anadhesive-repelling layer; and

FIG. 4 is a detail view and shows diagrammatically on an enlarged scalea section through a lattice opening, in which is disposed the filmconsisting of elastomeric material.

Referring to the drawings more in detail;

FIG. 1 shows an open wide-mesh woven fabric, the warp threads 1 and weftthreads 2, the threads in each being at equal spacings from one another.The openings or meshes thus formed in the woven fabric are closed bythin films 3 of elastomeric material. The films can consist of naturalrubber, artificial rubber or other elastomeric plastics or mixturesthereof. The distance of the Warp and weft threads from one another iskept constant by the thin films formed in the openings.

The embodiment shown in FIG. 2 comprises (when viewed perpendicularly tothe plane of the drawing) a lattice material consisting of superimposedfront warp threads 4, weft threads 5 disposed between them and rear warpthreads 6. As will be seen the rear warp threads 6 are arrangedstaggered in relation to the front warp threads 4. They can also bedisposed in alignment with the front warp threads 4.

The meshes or openings of the lattice material thus formed are againclosed by thin films of elastomeric material.

In FIG. 3 the lattice material of FIG. 2 is further provided with anupper adhesive-repelling layer 7 and a lower layer of apressure-sensitive adhesive composition 8. The upper adhesive-repellinglayer and the adhesive composition adhere firmly to the supportconsisting of the lattice material, the openings of which are closed bythin films of elastomeric material.

The detail view of FIG. 4 shows the formation of the filnTs in theopenings within the lattice material. In this figure it will be notedthat the film 3 which closes the mesh is meniscus shaped being thinnerin the center and thicker at the portions where it contacts thefilaments.

The following example illustrates the invention:

Example I A web according to FIG. 1 can for example be manufactured asfollows:

A lattice-like woven fabric was manufactured from 400 denier twistlessyarns each of 1000 filaments of highstrength viscose rayon, the threadspacing in both warp and weft being about 3 mm. Immediately aftermanufacture the fabric was impregnated with a 30% by weight dispersionof butadiene acrylonitrile copolymer or of butyl rubber, the dispersioncontaining a small quantity of thiuramdisulphide. The fabric was drawnthrough the dispersion just after the sley of the loom by co-operatingapplicator and squeezing cylinders, one of which has an elastic surface.

T he treated lattice-like fabric was thereupon dried in air andvulcanised by being brought into contact with a heated cylinder. In thefinal product, the separate openings in the lattice were closed by thinfilms of vulcanised synthetic rubber, which in addition to closing theinterstices at the same time effectively prevented a relativedisplacement of the threads of the fabric. The product had a very hightensile strength, a good bending and breaking strength, excellentresistance to tearing and high impact resistance.

Example II A web according to FIG. 2 may for example be manufactured asfollows:

A lattice material consisting of glass filaments No. 50 (180 denier), inwhich the warp and weft are laid one upon the other and are not wovenand which has a filament spacing (warp and weft) of about 4 mm.,immediately after leaving the machine used for the manufacture thereof(French Patent 1,208,968) is coated with a polyvinyl chloride plastisol(polyvinyl chloride in dioctylphthalate) with a content of 1% ofhexamethylene-diisocyanate on a coating machine and thereafter subjectedto doctoring. After drying in air and after a heat treatment, theopenings in the lattice material are satisfactorily closed by thinfilms. The underside of the web thus obtained is then coated with aself-adhesive composition of known type consisting of rubber, resin,filler and age resistor, while the top surface is provided with acoating consisting of an adhesive-repelling composition based onsilicone or based on polyvinyl stearate.

Adhesive tapes manufactured from the web exhibit excellent properties,

The flexible foil-like web reinforced with filaments or threads inaccordance with the invention is distinguished by high tensile strengthlongitudinally and also (where high strength weft is used) transverselyand high bending and impact strengths. The warp and weft threads areanchored to one another by the films of elastomeric material and cannotbe displaced relatively to one another.

Tapes manufactured from the flexible foil-like web reinforced withfilaments are suitable as a binding material for many industrialpurposes, more especially for packing purposes.

The flexible foil-like web reinforced with filaments can also be usedfor packing and protecting purposes and is distinguished by aparticularly good resistance to chemical action and weather influences.

Sheets or tapes consisting of the filament-reinforced flexible foil-likeweb in accordance with the invention, provided with an adhesive layer,have high strength values and can be used instead of banding irons forthe closing of containers, boxes, cartons and also for banding heavy andbulky articles, for example bundles of rods.

What is claimed is:

An adhesive tape for high-strength packing comprising afilament-reinforced flexible foil-like web, of a largemesh latticematerial consisting of synthetic filaments having a spacing of from 2 to4 mm., in which the openings of the lattice are each closed by a thinfilm of an elastomeric plastic material, said film in each opening beingthin in the center and increasing in thickness in a meniscus to thepoint of contact with the filaments and a coating of apressure-sensitive adhesive on one side of the lattice material.

References Cited by the Examiner UNITED STATES PATENTS 1,580,287 4/26Colle et a1. 117-98 1,953,901 4/34 Ziegler 117-98 2,038,325 4/36 iVanCleef 117-68.5 2,451,865 10/48 OBrien 117-122 2,458,166 1/49 Homeyer117-122 2,593,553 4/52 Francis 117-98 2,905,584 9/59 Dunlap 117-1223,072,497 1/63 Guglielmo 117-49 3,085,027, 4/63 Porteous 117-163 FOREIGNPATENTS 790,159 2/58 Great Britain.

JOSEPH B. SPENCER, Primary Examiner.

RICHARD D. NEVIUS, Examiner,

